CosmoGirl-Sat

◎Main activities 
◆Registration of Amateur frequency band artificial satellite station license 
◆External report
◆Events related to artificial satellites will be held

We are working toward the launch in 2023.
The name of the satellite is the CosmoGirl-Sat, and here we will introduce the ground station and artificial satellite station of amateur satellite communication.

Satellite mission

The mission is entitled” Space Ema “and will carry out the following.
・APRS Digipiter
・Communication of image data
・Communication of character data

Launch information

・Scheduled to be launched
First half of 2023
・ Rocket name
to be decided
・ Launch location
to be decided
・ Orbital altitude
400km
・ Orbital shape
circular orbit
・ Orbital inclination
51.6 degree

Satellite system overview

The satellite receives commands from the ground station, processes the information with the built-in microcomputer, and sends the mission data. Electricity is generated by solar cells and charged into the batteries. A dipole antenna is used for communication.

Satellite body

・Satellite appearance
The satellite is a cube of 100 [mm] square called CubeSat and weighs about 1 kg.

・Control system
The control system uses the PIC of an 8-bit microcomputer.
The main control structure is that the following three microcomputers are connected to each other by UART.

<RESET PIC>
Controls the power supply for the entire CubeSat system.

<COM PIC>
Performs processing in communication with the ground station, such as receiving commands. Communicate with MAIN PIC via UART or flash memory. Housekeeping data and mission data are transferred from the MAIN PIC to the COM PIC and transmitted to the ground station by the UHF communication device. “

<MAIN PIC>
Process all satellite data. It also collects power system information from the RESET PIC. Most of the commands from the ground station are processed by the MAIN PIC. “

・Artificial satellite station call sign
※Applying

Ground station

The ground station uses Kantronix’s KPC9612 for the TNC and iCOM’s IC-9100M for the communication device.
The antenna uses a normal Yagi-Uda antenna and is installed on the roof of the building to avoid obstacles to the propagation path to the satellite passing over the sky.

・Ground station call sign
JS1YJX

Satellite communication

The satellite orbits the earth about every 90 minutes, appears to be moving over the ground, and passes over the ground station several times a day.
Communication operation with satellites is possible 3 to 5 times a day, and communication is usually possible for 5 to 15 minutes each time.


◎Operation flow
CubeSat uses CW for telemetry beacons to send basic satellite information.
CW is a radio wave with a constant frequency, and information transmits a combination of long and short sounds by Morse code ON / OFF of the signal.
Ground stations use two types of software to obtain telemetry information: CW Skimmer and CwGet.
Operation usually begins with catching the CW beacon and then takes the next step using frequency modulation (FM) communication.

1. (Download housekeeping data, send mission execution commands, download mission data, etc.)
2. Listen to CW telemetry
3. Check the basic satellite information (especially battery voltage, current) contained in CW telemetry.
4. If the battery voltage is sufficient, send the planned command
5. Confirm the response that the command was received (it can be a UHF FM packet)
6. If it is a data (housekeeping or mission data) download command, continue to send the data download command during the satellite visible time.
7. If you sent a mission execution command, the flag related to mission execution during CW telemetry will be changed, so check it.
8. Analyze CW telemetry data at satellite visible time or immediately after visible time to further examine for any abnormalities (temperature, reset state, etc.), and discuss any problems with everyone.